Online sales are more difficult to generate than simple banner hits or leads, so it's not a good idea to plan on making a killing from your virtual store, but be content that you are in a position to offer products directly to your viewers as an option for purchase.  Pages such as crafting and hobbies, automotive, graphics and software, plus household interests can do very well with product links.  While e-commerce is still in it's infancy and not readily accepted, it is growing as credit card and personal security issues are addressed.

Clothing and footwear products have proven to run a higher risk of returned items and cancelled orders, because of this your account earnings will fluctuate as products are returned.  Footwear is the most difficult since size and fit are not easy to determine online.  Clothing that is designed as one size fits all does better than fitted and sized clothing, and since color reproduction on a monitor is not accurate, many articles are returned simply because they are not the same color as the picture shown.

Product offers are a step towards becoming a virtual store, and while they can be very lucrative if properly presented with strong support content, they are often best used as a convenient method for your page guest to purchase an item mentioned in your pages.